Supersonic Boundary Condition

todd · March 23, 2009, 01:01

I have a nozzle exit boundary condition that is supersonic. My problem is that is a pulse flow, so some of the flow reaches the boundary condition as subsonic. This causes linear solver failures in CFX. Does anyone know how to handle this?

ghorrocks · March 23, 2009, 22:43

Hi,

Is it possible to extend your domain so the entire exit boundary is subsonic? The numerics will be much easier then.

Glenn Horrocks

todd · March 24, 2009, 20:26

Thanks, Glenn. I have tried to move the BC further downstream, but you may be right. The easiest soltion is to extend it even further, until it converges. I'll try that and some other techniques that I have seen on some other threads.

March 23, 2009, 01:01	Supersonic Boundary Condition	#1
todd New Member Todd Travis Join Date: Mar 2009 Posts: 2 Rep Power: 0	I have a nozzle exit boundary condition that is supersonic. My problem is that is a pulse flow, so some of the flow reaches the boundary condition as subsonic. This causes linear solver failures in CFX. Does anyone know how to handle this?

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Boundary Conditions	Thomas P. Abraham	Main CFD Forum	20	July 7, 2013 05:05
inlet velocity boundary condition	murali	CFX	5	August 3, 2012 08:56
spanwiperiodic boundary condition for LES	Sungho Yoon	CFX	5	July 8, 2008 06:21
1 and 2 Order Boundary condition at the same place	CFD_Flo	Main CFD Forum	4	July 11, 2005 11:57
Pressure Boundary Condition	Matt Umbel	Main CFD Forum	0	January 11, 2002 10:06

March 23, 2009, 22:43		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,700 Rep Power: 143	Hi, Is it possible to extend your domain so the entire exit boundary is subsonic? The numerics will be much easier then. Glenn Horrocks

March 24, 2009, 20:26		#3
todd New Member Todd Travis Join Date: Mar 2009 Posts: 2 Rep Power: 0	Thanks, Glenn. I have tried to move the BC further downstream, but you may be right. The easiest soltion is to extend it even further, until it converges. I'll try that and some other techniques that I have seen on some other threads.